Alternative modulation for a random access message in a two-step random access procedure

ABSTRACT

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine a set of modulations for a random access message associated with a two-step random access channel (RACH) procedure. The set of modulations may be either a first set of modulations or a second set of modulations that is different from the first set of modulations. The set of modulations may be determined based at least in part on whether a signal strength satisfies a signal strength threshold. The UE may transmit the random access message based at least in part on the determined set of modulations. The random access message may include a physical uplink shared channel modulated using the determined set of modulations. Numerous other aspects are provided.

CROSS-REFERENCE TO RELATED APPLICATION

This Patent Application claims priority to U.S. Provisional PatentApplication No. 62/968,913, filed on Jan. 31, 2020, entitled“ALTERNATIVE MODULATION FOR A RANDOM ACCESS MESSAGE IN A TWO-STEP RANDOMACCESS PROCEDURE,” and assigned to the assignee hereof. The disclosureof the prior Application is considered part of and is incorporated byreference into this Patent Application.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wirelesscommunication and to techniques and apparatuses for alternativemodulation for a random access message in a two-step random accessprocedure.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, and/or the like). Examples of such multiple-accesstechnologies include code division multiple access (CDMA) systems, timedivision multiple access (TDMA) systems, frequency-division multipleaccess (FDMA) systems, orthogonal frequency-division multiple access(OFDMA) systems, single-carrier frequency-division multiple access(SC-FDMA) systems, time division synchronous code division multipleaccess (TD-SCDMA) systems, and Long Term Evolution (LTE).LTE/LTE-Advanced is a set of enhancements to the Universal MobileTelecommunications System (UMTS) mobile standard promulgated by theThird Generation Partnership Project (3GPP).

A wireless communication network may include a number of base stations(BSs) that can support communication for a number of user equipment(UEs). A user equipment (UE) may communicate with a base station (BS)via the downlink and uplink. The downlink (or forward link) refers tothe communication link from the BS to the UE, and the uplink (or reverselink) refers to the communication link from the UE to the BS. As will bedescribed in more detail herein, a BS may be referred to as a Node B, agNB, an access point (AP), a radio head, a transmit receive point (TRP),a New Radio (NR) BS, a 5G Node B, and/or the like.

The above multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent user equipment to communicate on a municipal, national,regional, and even global level. New Radio (NR), which may also bereferred to as 5G, is a set of enhancements to the LTE mobile standardpromulgated by the Third Generation Partnership Project (3GPP). NR isdesigned to better support mobile broadband Internet access by improvingspectral efficiency, lowering costs, improving services, making use ofnew spectrum, and better integrating with other open standards usingorthogonal frequency division multiplexing (OFDM) with a cyclic prefix(CP) (CP-OFDM) on the downlink (DL), using CP-OFDM and/or SC-FDM (e.g.,also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) onthe uplink (UL), as well as supporting beamforming, multiple-inputmultiple-output (MIMO) antenna technology, and carrier aggregation.However, as the demand for mobile broadband access continues toincrease, there exists a need for further improvements in LTE and NRtechnologies. Preferably, these improvements should be applicable toother multiple access technologies and the telecommunication standardsthat employ these technologies.

SUMMARY

In some aspects, a method of wireless communication, performed by a UE,may include determining a set of modulations for a random access messageassociated with a two-step random access channel (RACH) procedure,wherein the set of modulations is either a first set of modulations or asecond set of modulations, the first set of modulations being differentfrom the second set of modulations, and wherein the set of modulationsis determined based at least in part on whether a signal strengthsatisfies a signal strength threshold; and transmitting the randomaccess message based at least in part on the determined set ofmodulations, the random access message including a physical uplinkshared channel (PUSCH) modulated using the determined set ofmodulations.

In some aspects, a method of wireless communication, performed by a basestation, may include receiving, from a UE, a random access messageassociated with a two-step RACH procedure; determining, based at leastin part on the random access message, a set of modulations associatedwith the random access message, wherein the set of modulations is eithera first set of modulations or a second set of modulations, the first setof modulations being different from the second set of modulations; andprocessing the random access message based at least in part on thedetermined set of modulations associated with the random access message,the random access message including a PUSCH modulated using thedetermined set of modulations.

In some aspects, a UE for wireless communication may include a memoryand one or more processors operatively coupled to the memory. The memoryand the one or more processors may be configured to determine a set ofmodulations for a random access message associated with a two-step RACHprocedure, wherein the set of modulations is either a first set ofmodulations or a second set of modulations, the first set of modulationsbeing different from the second set of modulations, and wherein the setof modulations is determined based at least in part on whether a signalstrength satisfies a signal strength threshold; and transmit the randomaccess message based at least in part on the determined set ofmodulations, the random access message including a PUSCH modulated usingthe determined set of modulations.

In some aspects, a base station for wireless communication may include amemory and one or more processors operatively coupled to the memory. Thememory and the one or more processors may be configured to receive, froma UE, a random access message associated with a two-step RACH procedure;determine, based at least in part on the random access message, a set ofmodulations associated with the random access message, wherein the setof modulations is either a first set of modulations or a second set ofmodulations, the first set of modulations being different from thesecond set of modulations; and process the random access message basedat least in part on the determined set of modulations associated withthe random access message, the random access message including a PUSCHmodulated using the determined set of modulations.

In some aspects, a non-transitory computer-readable medium may store oneor more instructions for wireless communication. The one or moreinstructions, when executed by one or more processors of a UE, may causethe one or more processors to determine a set of modulations for arandom access message associated with a two-step RACH procedure, whereinthe set of modulations is either a first set of modulations or a secondset of modulations, the first set of modulations being different fromthe second set of modulations, and wherein the set of modulations isdetermined based at least in part on whether a signal strength satisfiesa signal strength threshold; and transmit the random access messagebased at least in part on the determined set of modulations, the randomaccess message including a PUSCH modulated using the determined set ofmodulations.

In some aspects, a non-transitory computer-readable medium may store oneor more instructions for wireless communication. The one or moreinstructions, when executed by one or more processors of a base station,may cause the one or more processors to receive, from a UE, a randomaccess message associated with a two-step RACH procedure; determine,based at least in part on the random access message, a set ofmodulations associated with the random access message, wherein the setof modulations is either a first set of modulations or a second set ofmodulations, the first set of modulations being different from thesecond set of modulations; and process the random access message basedat least in part on the determined set of modulations associated withthe random access message, the random access message including a PUSCHmodulated using the determined set of modulations.

In some aspects, an apparatus for wireless communication may includemeans for determining a set of modulations for a random access messageassociated with a two-step RACH procedure, wherein the set ofmodulations is either a first set of modulations or a second set ofmodulations, the first set of modulations being different from thesecond set of modulations, and wherein the set of modulations isdetermined based at least in part on whether a signal strength satisfiesa signal strength threshold; and means for transmitting the randomaccess message based at least in part on the determined set ofmodulations, the random access message including a PUSCH modulated usingthe determined set of modulations.

In some aspects, an apparatus for wireless communication may includemeans for receiving, from a UE, a random access message associated witha two-step RACH procedure; means for determining, based at least in parton the random access message, a set of modulations associated with therandom access message, wherein the set of modulations is either a firstset of modulations or a second set of modulations, the first set ofmodulations being different from the second set of modulations; andmeans for processing the random access message based at least in part onthe determined set of modulations associated with the random accessmessage, the random access message including a PUSCH modulated using thedetermined set of modulations.

Aspects generally include a method, apparatus, system, computer programproduct, non-transitory computer-readable medium, user equipment, basestation, wireless communication device, and/or processing system assubstantially described herein with reference to and as illustrated bythe drawings and specification.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purposesof illustration and description, and not as a definition of the limitsof the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can beunderstood in detail, a more particular description, briefly summarizedabove, may be had by reference to aspects, some of which are illustratedin the appended drawings. It is to be noted, however, that the appendeddrawings illustrate only certain typical aspects of this disclosure andare therefore not to be considered limiting of its scope, for thedescription may admit to other equally effective aspects. The samereference numbers in different drawings may identify the same or similarelements.

FIG. 1 is a block diagram conceptually illustrating an example of awireless communication network, in accordance with various aspects ofthe present disclosure.

FIG. 2 is a block diagram conceptually illustrating an example of a basestation in communication with a UE in a wireless communication network,in accordance with various aspects of the present disclosure.

FIG. 3 is a diagram illustrating an example of selection of a set ofmodulations for a random access message in a two-step RACH procedure, inaccordance with various aspects of the present disclosure.

FIG. 4 is a diagram illustrating an example process performed, forexample, by a user equipment, in accordance with various aspects of thepresent disclosure.

FIG. 5 is a diagram illustrating an example process performed, forexample, by a base station, in accordance with various aspects of thepresent disclosure.

FIG. 6 is a conceptual data flow diagram illustrating an example of adata flow between different components in an example apparatus.

FIG. 7 is a diagram illustrating an example of a hardware implementationfor an apparatus employing a processing system.

FIG. 8 is a conceptual data flow diagram illustrating an example of adata flow between different components in an example apparatus.

FIG. 9 is a diagram illustrating an example of a hardware implementationfor an apparatus employing a processing system.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein one skilled in the art should appreciate that the scopeof the disclosure is intended to cover any aspect of the disclosuredisclosed herein, whether implemented independently of or combined withany other aspect of the disclosure. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure disclosed hereinmay be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented withreference to various apparatuses and techniques. These apparatuses andtechniques will be described in the following detailed description andillustrated in the accompanying drawings by various blocks, modules,components, circuits, steps, processes, algorithms, and/or the like(collectively referred to as “elements”). These elements may beimplemented using hardware, software, or combinations thereof. Whethersuch elements are implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem.

It should be noted that while aspects may be described herein usingterminology commonly associated with 3G and/or 4G wireless technologies,aspects of the present disclosure can be applied in othergeneration-based communication systems, such as 5G and later, includingNR technologies.

FIG. 1 is a diagram illustrating a wireless network 100 in which aspectsof the present disclosure may be practiced. The wireless network 100 maybe an LTE network or some other wireless network, such as a 5G or NRnetwork. The wireless network 100 may include a number of BSs 110 (shownas BS 110 a, BS 110 b, BS 110 c, and BS 110 d) and other networkentities. ABS is an entity that communicates with user equipment (UEs)and may also be referred to as a base station, a NR BS, a Node B, a gNB,a 5G node B (NB), an access point, a transmit receive point (TRP),and/or the like. Each BS may provide communication coverage for aparticular geographic area. In 3GPP, the term “cell” can refer to acoverage area of a BS and/or a BS subsystem serving this coverage area,depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or another type of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). ABS for a macro cell may bereferred to as a macro BS. ABS for a pico cell may be referred to as apico BS. A BS for a femto cell may be referred to as a femto BS or ahome BS. In the example shown in FIG. 1, a BS 110 a may be a macro BSfor a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102b, and a BS 110 c may be a femto BS for a femto cell 102 c. A BS maysupport one or multiple (e.g., three) cells. The terms “eNB”, “basestation”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” maybe used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile BS. In some aspects, the BSs may be interconnected to one anotherand/or to one or more other BSs or network nodes (not shown) in thewireless network 100 through various types of backhaul interfaces suchas a direct physical connection, a virtual network, and/or the likeusing any suitable transport network.

Wireless network 100 may also include relay stations. A relay station isan entity that can receive a transmission of data from an upstreamstation (e.g., a BS or a UE) and send a transmission of the data to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that can relay transmissions for other UEs. In the example shown inFIG. 1, a relay station 110 d may communicate with macro BS 110 a and aUE 120 d in order to facilitate communication between BS 110 a and UE120 d. A relay station may also be referred to as a relay BS, a relaybase station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/orthe like. These different types of BSs may have different transmit powerlevels, different coverage areas, and different impacts on interferencein wireless network 100. For example, macro BSs may have a high transmitpower level (e.g., 5 to 40 Watts) whereas pico BSs, femto BSs, and relayBSs may have lower transmit power levels (e.g., 0.1 to 2 Watts).

A network controller 130 may couple to a set of BSs and may providecoordination and control for these BSs. Network controller 130 maycommunicate with the BSs via a backhaul. The BSs may also communicatewith one another, e.g., directly or indirectly via a wireless orwireline backhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelessnetwork 100, and each UE may be stationary or mobile. A UE may also bereferred to as an access terminal, a terminal, a mobile station, asubscriber unit, a station, and/or the like. A UE may be a cellularphone (e.g., a smart phone), a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, a medical device or equipment, biometric sensors/devices,wearable devices (smart watches, smart clothing, smart glasses, smartwrist bands, smart jewelry (e.g., smart ring, smart bracelet)), anentertainment device (e.g., a music or video device, or a satelliteradio), a vehicular component or sensor, smart meters/sensors,industrial manufacturing equipment, a global positioning system device,or any other suitable device that is configured to communicate via awireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolvedor enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEsinclude, for example, robots, drones, remote devices, sensors, meters,monitors, location tags, and/or the like, that may communicate with abase station, another device (e.g., remote device), or some otherentity. A wireless node may provide, for example, connectivity for or toa network (e.g., a wide area network such as Internet or a cellularnetwork) via a wired or wireless communication link. Some UEs may beconsidered Internet-of-Things (IoT) devices, and/or may be implementedas NB-IoT (narrowband internet of things) devices. Some UEs may beconsidered a Customer Premises Equipment (CPE). UE 120 may be includedinside a housing that houses components of UE 120, such as processorcomponents, memory components, and/or the like.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular radioaccess technology (RAT) and may operate on one or more frequencies. ARAT may also be referred to as a radio technology, an air interface,and/or the like. A frequency may also be referred to as a carrier, afrequency channel, and/or the like. Each frequency may support a singleRAT in a given geographic area in order to avoid interference betweenwireless networks of different RATs. In some cases, NR or 5G RATnetworks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120 a and UE 120e) may communicate directly using one or more sidelink channels (e.g.,without using a base station 110 as an intermediary to communicate withone another). For example, the UEs 120 may communicate usingpeer-to-peer (P2P) communications, device-to-device (D2D)communications, a vehicle-to-everything (V2X) protocol (e.g., which mayinclude a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure(V2I) protocol, and/or the like), a mesh network, and/or the like. Inthis case, the UE 120 may perform scheduling operations, resourceselection operations, and/or other operations described elsewhere hereinas being performed by the base station 110.

In some aspects, a UE 120 and/or a base station 110 may perform one ormore operations associated with selecting a set of modulations for arandom access message in a two-step random access procedure. Forexample, the UE 120 may determine a set of modulations for a randomaccess message associated with the two-step RACH procedure, as describedherein. In some aspects, the message type may be either a first set ofmodulations or a second set of modulations, where the second set ofmodulations is selected or designed to provide coverage enhancement forthe random access message. In some aspects, the UE 120 may determine theset of modulations based at least in part on whether a signal strengthsatisfies a threshold. After determining the set of modulations, the UE120 may transmit the random access message accordingly (e.g., bymodulating a PUSCH payload of the random access message using thedetermined set of modulations). In some aspects, a base station 110 mayreceive the random access message associated with the two-step RACHprocedure, determine the set of modulations, and process the randomaccess message accordingly, as described herein. In this way, benefitsprovided by the two-step RACH procedure (e.g., reduction in signalingoverhead and/or latency, improvement in RACH capacity and/or powerefficiency) can be realized, while coverage of the random access messagemay be increased.

As indicated above, FIG. 1 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 1.

FIG. 2 shows a block diagram of a design 200 of base station 110 and UE120, which may be one of the base stations and one of the UEs in FIG. 1.Base station 110 may be equipped with T antennas 234 a through 234 t,and UE 120 may be equipped with R antennas 252 a through 252 r, where ingeneral T≥1 and R≥1.

At base station 110, a transmit processor 220 may receive data from adata source 212 for one or more UEs, select one or more modulation andcoding schemes (MCS) for each UE based at least in part on channelquality indicators (CQIs) received from the UE, process (e.g., encodeand modulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 220 may also process system information (e.g., for semi-staticresource partitioning information (SRPI) and/or the like) and controlinformation (e.g., CQI requests, grants, upper layer signaling, and/orthe like) and provide overhead symbols and control symbols. Transmitprocessor 220 may also generate reference symbols for reference signals(e.g., the cell-specific reference signal (CRS)) and synchronizationsignals (e.g., the primary synchronization signal (PSS) and secondarysynchronization signal (SSS)). A transmit (TX) multiple-inputmultiple-output (MIMO) processor 230 may perform spatial processing(e.g., precoding) on the data symbols, the control symbols, the overheadsymbols, and/or the reference symbols, if applicable, and may provide Toutput symbol streams to T modulators (MODs) 232 a through 232 t. Eachmodulator 232 may process a respective output symbol stream (e.g., forOFDM and/or the like) to obtain an output sample stream. Each modulator232 may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal. Tdownlink signals from modulators 232 a through 232 t may be transmittedvia T antennas 234 a through 234 t, respectively. According to variousaspects described in more detail below, the synchronization signals canbe generated with location encoding to convey additional information.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom base station 110 and/or other base stations and may providereceived signals to demodulators (DEMODs) 254 a through 254 r,respectively. Each demodulator 254 may condition (e.g., filter, amplify,downconvert, and digitize) a received signal to obtain input samples.Each demodulator 254 may further process the input samples (e.g., forOFDM and/or the like) to obtain received symbols. A MIMO detector 256may obtain received symbols from all R demodulators 254 a through 254 r,perform MIMO detection on the received symbols if applicable, andprovide detected symbols. A receive processor 258 may process (e.g.,demodulate and decode) the detected symbols, provide decoded data for UE120 to a data sink 260, and provide decoded control information andsystem information to a controller/processor 280. A channel processormay determine reference signal received power (RSRP), received signalstrength indicator (RSSI), reference signal received quality (RSRQ),channel quality indicator (CQI), and/or the like. In some aspects, oneor more components of UE 120 may be included in a housing.

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) fromcontroller/processor 280. Transmit processor 264 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by modulators 254 a through 254 r (e.g.,for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to basestation 110. At base station 110, the uplink signals from UE 120 andother UEs may be received by antennas 234, processed by demodulators232, detected by a MIMO detector 236 if applicable, and furtherprocessed by a receive processor 238 to obtain decoded data and controlinformation sent by UE 120. Receive processor 238 may provide thedecoded data to a data sink 239 and the decoded control information tocontroller/processor 240. Base station 110 may include communicationunit 244 and communicate to network controller 130 via communicationunit 244. Network controller 130 may include communication unit 294,controller/processor 290, and memory 292.

Controller/processor 240 of base station 110, controller/processor 280of UE 120, and/or any other component(s) of FIG. 2 may perform one ormore techniques associated with alternative modulation for a randomaccess message in a two-step random access procedure, as described inmore detail elsewhere herein. For example, controller/processor 240 ofbase station 110, controller/processor 280 of UE 120, and/or any othercomponent(s) of FIG. 2 may perform or direct operations of, for example,process 400 of FIG. 4, process 500 of FIG. 5, and/or other processes asdescribed herein. Memories 242 and 282 may store data and program codesfor base station 110 and UE 120, respectively. In some aspects, memory242 and/or memory 282 may comprise a non-transitory computer-readablemedium storing one or more instructions for wireless communication. Forexample, the one or more instructions, when executed by one or moreprocessors of the base station 110 and/or the UE 120, may perform ordirect operations of, for example, process 400 of FIG. 4, process 500 ofFIG. 5, and/or other processes as described herein. A scheduler 246 mayschedule UEs for data transmission on the downlink and/or uplink.

In some aspects, UE 120 may include means for determining a set ofmodulations for a random access message associated with a two-step RACHprocedure, wherein the set of modulations is either a first set ofmodulations or a second set of modulations, the first set of modulationsbeing different from the second set of modulations, and wherein the setof modulations is determined based at least in part on whether a signalstrength satisfies a signal strength threshold; means for transmittingthe random access message based at least in part on the determined setof modulations, the random access message including a PUSCH modulatedusing the determined set of modulations; and/or the like. In someaspects, such means may include one or more components of UE 120described in connection with FIG. 2, such as controller/processor 280,transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252,DEMOD 254, MIMO detector 256, receive processor 258, and/or the like.

In some aspects, base station 110 may include means for receiving, froma UE (e.g., a UE 120), a random access message associated with atwo-step RACH procedure; means for determining, based at least in parton the random access message, a set of modulations associated with therandom access message, wherein the set of modulations is either a firstset of modulations or a second set of modulations, the first set ofmodulations being different from the second set of modulations; meansfor processing the random access message based at least in part on thedetermined set of modulations associated with the random access message,the random access message including a PUSCH modulated using thedetermined set of modulations; and/or the like. In some aspects, suchmeans may include one or more components of base station 110 describedin connection with FIG. 2, such as antenna 234, DEMOD 232, MIMO detector236, receive processor 238, controller/processor 240, transmit processor220, TX MIMO processor 230, MOD 232, antenna 234, and/or the like.

As indicated above, FIG. 2 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 2.

A two-step RACH procedure includes two steps (rather than four steps, asin a traditional four-step RACH procedure). The two-step RACH procedurecan, in some cases, provide a reduction in signaling overhead and/orlatency, and can provide improvement in RACH capacity and/or powerefficiency. In the two-step RACH procedure, a UE transmits a randomaccess message (referred to as msgA) that includes a preamble and apayload (e.g., a physical uplink shared channel (PUSCH) payload) of aconfigurable size (e.g., from a few bytes to a few hundred bytes). Thepreamble may assist with a timing offset estimation performed by a basestation. In general, the UE transmits the preamble and then transmitsthe payload after a configurable amount of time (e.g., including a guardperiod and/or a transmission gap). Here, the configurable amount of timemay serve to mitigate interference (e.g., inter-symbol interference(ISI), inter-carrier interference (ICI), and/or the like). The preambleand the payload can be transmitted in the same slot or in differentslots.

Multiple UEs performing the two-step RACH procedure can share a samePUSCH occasion. That is, multiple UEs performing the two-step RACHprocedure can share a same set of resources for transmitting randomaccess message payloads. Such sharing may occur when, for example, therandom access messages of the multiple UEs use similar modulation andcoding schemes (MCSs), similar waveforms, or similar payload sizes.Resource allocation for a given PUSCH occasion can be specified relativeto a RACH occasion (e.g., a set of resources for transmitting randomaccess message preambles), for example, by semi-statically ordynamically configured offsets in time and/or frequency. Both separateand shared RACH occasions can be configured for two-step RACH. Further,when a RACH occasion is shared between a two-step RACH procedure and afour-step RACH procedure, a pool of preambles can be partitioned intomutually exclusive subsets, each of which is associated with a differenttype of RACH procedure.

A base station may receive the random access message associated with thetwo-step RACH procedure, and may detect the preamble and decode thepayload. The base station may then transmit a random access response(referred to as msgB in the case of a two-step RACH procedure) to theUE. The random access response includes a physical downlink controlchannel (PDCCH) communication and a physical downlink shared channel(PDSCH) payload. Here, the PDCCH communication identifies a set ofresources of the PDSCH payload that carries information for the UE. ThePDSCH payload can include, for example, contention resolutioninformation for the UE, a cell radio network temporary identifier(C-RNTI) for the UE, a timing advance (TA) command for the UE, and/orthe like.

As described above, the aim of the two-step RACH procedure is to providea reduction in signaling overhead and/or latency, and an improvement inRACH capacity and/or power efficiency (e.g., as compared to thefour-step RACH procedure). It is therefore desirable to enable increasedcoverage of the random access message of the two-step RACH procedure(e.g., to allow the two-step RACH procedure to be used, while achievingacceptable coverage). In some cases, coverage enhancement for the randomaccess message of the two-step RACH procedure can be provided bysupporting different modulations for the payload portion of the randomaccess message.

Some techniques and apparatuses described herein provide techniques andapparatuses for selection of a set of modulations for a random accessmessage of a two-step RACH procedure. In some aspects, a UE maydetermine a set of modulations for the random access message associatedwith the two-step RACH procedure, where the set of modulations is eithera first set of modulations (e.g., quadrature phase shift keying (QPSK),16 quadrature amplitude modulation (QAM), 64 QAM, and/or the like) or asecond set of modulations (e.g., an alternative to the first set ofmodulations, such as a π/2 binary phase shift keying (BPSK) modulation).In some aspects, the UE may determine the set of modulations based atleast in part on whether a signal strength satisfies a signal strengththreshold. In this way, the above-described benefits of the two-stepRACH procedure can be realized, while coverage of the random accessmessage may be increased. Additional details are described below.

FIG. 3 is a diagram illustrating an example 300 of selection of a set ofmodulations for a random access message in a two-step RACH procedure, inaccordance with various aspects of the present disclosure.

As shown in FIG. 3 by reference 305, a base station (e.g., base station110) may transmit a synchronization signal block (SSB) (e.g., usingtransmit processor 220, controller/processor 240, memory 242,transmission component 810, and/or the like). In some aspects, the SSBmay include one or more synchronization signals and a physical broadcastchannel (PBCH), as described below. In general, in association withtransmitting a set of SSBs, the base station defines candidate positionsfor SSBs to be transmitted within a radio frame, and the quantity of acandidate positions corresponds to a quantity of beams radiated in agiven direction. Here, each SSB transmitted by the base station may beassociated with a respective SSB index. As further indicated byreference 305, a UE (e.g., UE 120) may receive (e.g., using receiveprocessor 258, controller/processor 280, memory 282, reception component604, and/or the like) an SSB transmitted by the base station.

As shown by reference 310, the UE may determine (e.g., using receiveprocessor 258, controller/processor 280, memory 282, determinationcomponent 606, and/or the like) a signal strength based at least in parton a reference signal received power (RSRP) associated with the SSB. Insome aspects, the UE may measure a signal strength of a reference signal(e.g., a demodulation reference signal (DMRS)) of each SSB detected bythe UE (e.g., within a particular period of time, such as a period ofone SSB set) and, based on results of these measurements, may identifyan SSB for which the reference signal has a suitable (e.g., strongest)signal strength. Here, the SSB with the suitable signal strength uses asuitable (e.g., best) beam for the UE.

In some aspects, after identifying the suitable beam, the UE may thendecode the PBCH associated with the SSB. The PBCH may carry, forexample, system information (e.g., a master information block (MIB), oneor more system information blocks (SIBs), and/or the like), aconfiguration for remaining minimum system information (RMSI), and oneor more other items of information. Here, decoding the PBCH enables theUE to receive a subsequent physical downlink control channel (PDCCH) anda physical downlink shared channel (PDSCH) that schedule and carry,respectively, RMSI and other system information (OSI). In some aspects,the configuration of the PDCCH for the RMSI may be determined from thePBCH, and a control resource set (CORESET) configuration for the RMSImay be determined based at least in part on an SSB index of the SSB.

As indicated by reference 315, the UE may determine (e.g., using receiveprocessor 258, transmit processor 264, controller/processor 280, memory282, determination component 606, and/or the like) a set of modulationsfor a random access message associated with the two-step RACH procedure.In some aspects, the set of modulations may be either a first set ofmodulations or a second set of modulations (e.g., an alternative set ofmodulations that differs from the first set of modulations). In someaspects, the first set of modulations may include one or moremodulations typically used for a first message in the two-step RACHprocedure (e.g., when coverage enhancement is not provided), such asQPSK, 16 QAM, 64 QAM, and/or the like. In some aspects, the second oneor more may include one or more modulations, such as π/2 BPSKmodulation. In some aspects, the second set of modulations may beselected or designed so as to provide coverage enhancement for therandom access message associated with the two-step RACH procedure.

In some aspects, the UE may determine the set of modulations based atleast in part on whether the signal strength satisfies a signal strengththreshold associated with identifying a set of modulations for a randomaccess message for a two-step RACH procedure (herein referred tothreshold Th). As an example, the UE may determine the signal strengthbased at least in part on the RSRP associated with the SSB, as describedabove. The UE may then compare the signal strength to the threshold Th.Here, if the signal strength satisfies the threshold Th (e.g., when thesignal strength is greater than or equal to the threshold Th), then theUE may determine that the UE is to use the first set of modulations forthe random access message of the two-step RACH procedure. Conversely, ifthe signal strength does not satisfy the threshold Th (e.g., when thesignal strength is less than the threshold Th), then the UE maydetermine that the UE is to the second set of modulations for the randomaccess message of the two-step RACH procedure. In some aspects, thethreshold Th may be identified in system information (e.g., RMSI)received by the UE from the base station in the manner described above.Thus, in some aspects, the threshold Th may be configured on the UE bythe base station.

As shown by reference 320, the UE may transmit (e.g., using transmitprocessor 264, controller/processor 280, memory 282, transmissioncomponent 608, and/or the like) the random access message, associatedwith the two-step RACH procedure, based at least in part on thedetermined set of modulations. That is, the UE may transmit the randomaccess message such that the random access message includes a PUSCHmodulated using the determined set of modulations. For example, the UEmay transmit the random access message including a PUSCH modulated usingthe first set of modulations when the UE determines that the first setof modulations is to be used for the random access message of thetwo-step RACH procedure. Alternatively, the UE may transmit the randomaccess message including a PUSCH modulated using the second set ofmodulations when the UE determines that the second set of modulations isto be used for the random access message of the two-step RACH procedure.

In some aspects, an amount of time between a preamble of the randomaccess message and the PUSCH may be based at least in part on thedetermined set of modulations. For example, when the UE is to use thesecond set of modulations, the UE may be configured to transmit therandom access message such that a gap between the preamble and the PUSCHis less than particular amount of time (e.g., 1 slot, 0.25 milliseconds,and/or the like). In such a case, the preamble of the random accessmessage may be used for channel estimation enhancement of the PUSCH.

In some aspects, a set of PUSCH resource unit groups associated with thefirst set of modulations may be different from a set of PUSCH resourceunit groups associated with the second set of modulations. For example,a PUSCH resource unit group associated with the second set ofmodulations may have more resource blocks (e.g., two times the number ofresource blocks) than a PUSCH resource unit group associated with thefirst set of modulations. Thus, in some aspects, a size of PUSCHresource unit group and/or a selection of a PUSCH resource unit groupmay differ depending on the set of modulations used for the PUSCH.

In some aspects, a set of RACH occasions associated with the first setof modulations may be different from a set of RACH occasions associatedwith the second set of modulations. Further, in some aspects, a mappingbetween a resource allocation for a PUSCH occasion and a RACH occasion,associated with the first set of modulations, may be different from amapping between a resource allocation for a PUSCH occasion and a RACHoccasion associated with the second set of modulations. Thus, in someaspects, RACH occasion and/or a mapping between a resource allocationfor a PUSCH occasion and a RACH occasion may differ depending on the setof modulations used for the PUSCH.

In some aspects, a payload of a random access message associated withthe first set of modulations may be different from a payload of a randomaccess message associated with the second set of modulations. Forexample, a PUSCH payload of a random access message that uses the secondset of modulations may be different (e.g., may have fewer bits) than aPUSCH payload of a random access message that uses the first set ofmodulations. Thus, in some aspects, a size of the PUSCH payload maydiffer depending on the set of modulations used for the PUSCH.

In some aspects, a length of a preamble for a random access message thatuses the first set of modulations may be different from a length of apreamble for a random access message that uses the second set ofmodulations. For example, a length of a preamble of a random accessmessage that uses the second set of modulations may be different (e.g.,greater than) a length of a preamble of a random access message thatuses the first random access message. Thus, in some aspects, a length ofthe preamble may differ depending on the set of modulations used for thePUSCH.

In some aspects, application of preamble repetition associated with thefirst set of modulations may be different from application of preamblerepetition associated with the second set of modulations. For example,preamble repetition may be applied for a random access message that usesthe second set of modulations, while preamble repetition may not beapplied for a random access message that uses the first set ofmodulations. Thus, in some aspects, application of preamble repetitionmay differ depending on the set of modulations used for the PUSCH.

In some aspects, a preamble sequence used for a random access messagethat uses the first set of modulations may be different from a preamblesequence used for a random access message that uses the second set ofmodulations. For example, a preamble sequence used for a random accessmessage that uses the second set of modulations may be selected from asecond set of preamble sequences, while a preamble sequence used for arandom access message that uses the first set of modulations may beselected from a first set of preamble sequences. Thus, in some aspects,a preamble sequence for a random access message may differ depending onthe set of modulations used for the PUSCH.

As shown by reference 325, the base station may receive (e.g., usingreceive processor 238, controller/processor 240, memory 242, receptioncomponent 804, and/or the like) the random access message associatedwith the two-step RACH procedure. The base station may determine (e.g.,using receive processor 238, controller/processor 240, memory 242,determination component 806, and/or the like) the set of modulationsassociated with the random access message. For example, the base stationmay determine the set of modulations based at least in part on theformat of the preamble (e.g., when the format of the preamble is aformat associated with a given set of modulations). As another example,the base station may determine the set of modulations based at least inpart on a length of a preamble of the random access message (e.g., whenthe length of the preamble is associated with a set of modulations). Asanother example, the base station may determine the set of modulationsbased at least in part on whether preamble repetition was applied forthe random access message (e.g., when application of preamble repetitionis indicative of a given set of modulations). As another example, thebase station may determine the set of modulations based at least in parton a preamble sequence of the random access message (e.g., when thepreamble sequence is one of a set of preamble sequences associated witha given set of modulations). As another example, the base station maydetermine the set of modulations based at least in part on a set ofresources in which the random access message is received (e.g., when aset of resources in which random access messages are communicated isdependent on the set of modulations used). Thus, in some aspects, aformat of a preamble of the random access message, a length of thepreamble, repetition of the preamble, a preamble sequence, and/or a setof resources in which the random access message is transmitted may serveas an indication of the set of modulations used by the UE, and the basestation may determine the set of modulations accordingly.

As shown by reference 330, the base station may process (e.g., usingtransmit processor 220, receive processor 238, controller/processor 240,memory 242, processing component 808, and/or the like) the random accessmessage based at least in part on determining the set of modulationsassociated with the random access message. For example, afterdetermining the set of modulations, the base station may demodulate thePUSCH based at least in part on the determined set of modulations, andmay determine the payload of the random access message. The base stationmay then proceed with the two-step RACH procedure (e.g., by preparingand transmitting msgB).

As indicated above, FIG. 3 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 3.

FIG. 4 is a diagram illustrating an example process 400 performed, forexample, by UE, in accordance with various aspects of the presentdisclosure. Example process 400 is an example where the UE (e.g., UE 120and/or the like) performs operations associated with alternativemodulation for a random access message in a two-step random accessprocedure.

As shown in FIG. 4, in some aspects, process 400 may include determininga set of modulations for a random access message associated with atwo-step RACH procedure (block 410). For example, the UE (e.g., usingreceive processor 258, transmit processor 264, controller/processor 280,memory 282, and/or the like) may determine a set of modulations for arandom access message associated with a two-step RACH procedure (e.g.,as described above in association with reference 315 of FIG. 3). In someaspects, the set of modulations is either a first set of modulations ora second set of modulations, the first set of modulations beingdifferent from the second set of modulations. In some aspects, the setof modulations is determined based at least in part on whether a signalstrength satisfies a signal strength threshold.

As further shown in FIG. 4, in some aspects, process 400 may includetransmitting the random access message based at least in part on thedetermined set of modulations (block 420). For example, the UE (e.g.,using receive processor 258, transmit processor 264,controller/processor 280, memory 282, and/or the like) may transmit therandom access message based at least in part on the determined set ofmodulations (e.g., as described above in association with reference 320of FIG. 3). In some aspects, the random access message includes a PUSCHmodulated using the determined set of modulations.

Process 400 may include additional aspects, such as any single aspect orany combination of aspects described below and/or in connection with oneor more other processes described elsewhere herein.

In a first aspect, the signal strength threshold is identified in systeminformation received by the UE.

In a second aspect, alone or in combination with the first aspect, thesystem information is carried by remaining minimum system information.

In a third aspect, alone or in combination with one or more of the firstand second aspects, the set of modulations is determined to be the firstset of modulations when the signal strength satisfies the signalstrength threshold, and is determined to be the second set ofmodulations when the signal strength does not satisfy the signalstrength threshold.

In a fourth aspect, alone or in combination with one or more of thefirst through third aspects, the second set of modulations is a π/2binary phase shift keying scheme.

In a fifth aspect, alone or in combination with one or more of the firstthrough fourth aspects, an amount of time between a preamble of therandom access message and the PUSCH is based at least in part on thedetermined set of modulations.

In a sixth aspect, alone or in combination with one or more of the firstthrough fifth aspects, the preamble of the random access message is usedfor channel estimation enhancement of the PUSCH.

In a seventh aspect, alone or in combination with one or more of thefirst through sixth aspects, a set of PUSCH resource unit groupsassociated with the first set of modulations is different from a set ofPUSCH resource unit groups associated with the second set ofmodulations.

In an eighth aspect, alone or in combination with one or more of thefirst through seventh aspects, a set of RACH occasions associated withthe first set of modulations is different from a set of RACH occasionsassociated with the second set of modulations.

In a ninth aspect, alone or in combination with one or more of the firstthrough eighth aspects, a mapping between a resource allocation for aPUSCH occasion and a RACH occasion, associated with the first set ofmodulations, is different from a mapping between a resource allocationfor a PUSCH occasion and a RACH occasion associated with the second setof modulations.

In a tenth aspect, alone or in combination with one or more of the firstthrough ninth aspects, a payload of a random access message associatedwith the first set of modulations, is different from a payload of arandom access message associated with the second set of modulations.

In an eleventh aspect, alone or in combination with one or more of thefirst through tenth aspects, process 400 includes receiving an SSB; anddetermining the signal strength based at least in part on a referencesignal received power associated with the SSB.

In a twelfth aspect, alone or in combination with one or more of thefirst through eleventh aspects, a length of a preamble for a randomaccess message that uses the first set of modulations is different froma length of a preamble for a random access message that uses the secondset of modulations.

In a thirteenth aspect, alone or in combination with one or more of thefirst through twelfth aspects, application of preamble repetition for arandom access message that uses the first set of modulations isdifferent from application of preamble repetition for a random accessmessage that uses the second set of modulations.

In a fourteenth aspect, alone or in combination with one or more of thefirst through thirteenth aspects, a preamble sequence used for a randomaccess message that uses the first set of modulations is different froma preamble sequence used for a random access message that uses thesecond set of modulations.

In a fifteenth aspect, alone or in combination with one or more of thefirst through fourteenth aspects, at least one of a format of a preambleof the random access message, a length of the preamble, repetition ofthe preamble, a preamble sequence, or a set of resources in which therandom access message is transmitted is used to indicate the determinedset of modulations.

Although FIG. 4 shows example blocks of process 400, in some aspects,process 400 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 4.Additionally, or alternatively, two or more of the blocks of process 400may be performed in parallel.

FIG. 5 is a diagram illustrating an example process 500 performed, forexample, by a base station, in accordance with various aspects of thepresent disclosure. Example process 500 is an example where the basestation (e.g., base station 110 and/or the like) performs operationsassociated with alternative modulation for a random access message in atwo-step random access procedure.

As shown in FIG. 5, in some aspects, process 500 may include receiving,from a UE, a random access message associated with a two-step RACHprocedure (block 510). For example, the base station (e.g., usingtransmit processor 220, receive processor 238, controller/processor 240,memory 242, and/or the like) may receive, from a UE (e.g., a UE 120), arandom access message associated with a two-step RACH procedure (e.g.,as described above in association with reference 325 of FIG. 3).

As further shown in FIG. 5, in some aspects, process 500 may includedetermining, based at least in part on the random access message, a setof modulations associated with the random access message (block 520).For example, the base station (e.g., using transmit processor 220,receive processor 238, controller/processor 240, memory 242, and/or thelike) may determine, based at least in part on the random accessmessage, a set of modulations associated with the random access message(e.g., (e.g., as described above in association with reference 325 ofFIG. 3). In some aspects, the set of modulations is either a first setof modulations or a second set of modulations, the first set ofmodulations being different from the second set of modulations.

As further shown in FIG. 5, in some aspects, process 500 may includeprocessing the random access message based at least in part on thedetermined set of modulations associated with the random access message(block 530). For example, the base station (e.g., using transmitprocessor 220, receive processor 238, controller/processor 240, memory242, and/or the like) may process the random access message based atleast in part on the determined set of modulations associated with therandom access message (e.g., as described above in association withreference 330 of FIG. 3). In some aspects, the random access messageincludes a PUSCH modulated using the determined set of modulations.

Process 500 may include additional aspects, such as any single aspect orany combination of aspects described below and/or in connection with oneor more other processes described elsewhere herein.

In a first aspect, a signal strength threshold, associated withdetermining to use the second set of modulations, is identified insystem information transmitted by the base station.

In a second aspect, alone or in combination with the first aspect, thesystem information is carried by remaining minimum system information.

In a third aspect, alone or in combination with one or more of the firstand second aspects, the second set of modulations is a π/2 binary phaseshift keying scheme.

In a fourth aspect, alone or in combination with one or more of thefirst through third aspects, an amount of time between a preamble of therandom access message and the PUSCH is based at least in part on thedetermined set of modulations.

In a fifth aspect, alone or in combination with one or more of the firstthrough fourth aspects, the preamble of the random access message isused for channel estimation enhancement of the PUSCH.

In a sixth aspect, alone or in combination with one or more of the firstthrough fifth aspects, a set of PUSCH resource unit groups associatedwith the first set of modulations is different from a set of PUSCHresource unit groups associated with the second set of modulations.

In a seventh aspect, alone or in combination with one or more of thefirst through sixth aspects, a set of RACH occasions associated with thefirst set of modulations is different from a set of RACH occasionsassociated with the second set of modulations.

In an eighth aspect, alone or in combination with one or more of thefirst through seventh aspects, a mapping between a resource allocationfor a PUSCH occasion and a RACH occasion, associated with the first setof modulations, is different from a mapping between a resourceallocation for a PUSCH occasion and a RACH occasion associated with thesecond set of modulations.

In a ninth aspect, alone or in combination with one or more of the firstthrough eighth aspects, a payload of a random access message associatedwith the first set of modulations, is different from a payload of arandom access message associated with the second set of modulations. Ina tenth aspect, alone or in combination with one or more of the firstthrough ninth aspects, process 500 includes transmitting a SSB to enablea determination of a signal strength of a reference signal receivedpower associated with the SSB.

In a tenth aspect, alone or in combination with one or more of the firstthrough ninth aspects, a length of a preamble for a random accessmessage that uses the first set of modulations is different from alength of a preamble for a random access message that uses the secondset of modulations.

In an eleventh aspect, alone or in combination with one or more of thefirst through tenth aspects, application of preamble repetition for arandom access message that uses the first set of modulations isdifferent from application of preamble repetition for a random accessmessage that uses the second set of modulations.

In a twelfth aspect, alone or in combination with one or more of thefirst through eleventh aspects, a preamble sequence used for a randomaccess message that uses the first set of modulations is different froma preamble sequence used for a random access message that uses thesecond set of modulations.

In a thirteenth aspect, alone or in combination with one or more of thefirst through twelfth aspects, the set of modulations is determinedbased at least in part on at least one of a format of a preamble of therandom access message, a length of the preamble, repetition of thepreamble, a preamble sequence, or a set of resources in which the randomaccess message is received.

Although FIG. 5 shows example blocks of process 500, in some aspects,process 500 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 5.Additionally, or alternatively, two or more of the blocks of process 500may be performed in parallel.

FIG. 6 is a conceptual data flow diagram 600 illustrating a data flowbetween different components in an example apparatus 602. The apparatus602 may be a UE (e.g., UE 120). In some aspects, the apparatus 602includes a reception component 604, a determination component 606,and/or a transmission component 608.

In some aspects, one or more components of apparatus 602 may operate toperform one or more operations described herein. For example, receptioncomponent 604 may operate to receive an SSB transmitted by a basestation (e.g., base station 110). Determination component 606 mayoperate to determine a signal strength based at least in part on an RSRPassociated with the SSB, and determine set of modulations for a randomaccess message associated with a two-step RACH procedure based at leastin part on whether a signal strength satisfies a signal strengththreshold. Transmission component 608 may operate to transmit (e.g., tobase station 650) the random access message based at least in part onthe determined set of modulations.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned process 400 of FIG. 4and/or the like. Each block in the aforementioned process 400 of FIG. 4and/or the like may be performed by a component and the apparatus mayinclude one or more of those components. The components may be one ormore hardware components specifically configured to carry out the statedprocesses/algorithm, implemented by a processor configured to performthe stated processes/algorithm, stored within a computer-readable mediumfor implementation by a processor, or some combination thereof.

The number and arrangement of components shown in FIG. 6 are provided asan example. In practice, there may be additional components, fewercomponents, different components, or differently arranged componentsthan those shown in FIG. 6. Furthermore, two or more components shown inFIG. 6 may be implemented within a single component, or a singlecomponent shown in FIG. 6 may be implemented as multiple, distributedcomponents. Additionally, or alternatively, a set of components (e.g.,one or more components) shown in FIG. 6 may perform one or morefunctions described as being performed by another set of componentsshown in FIG. 6.

FIG. 7 is a diagram 700 illustrating an example of a hardwareimplementation for an apparatus 602′ employing a processing system 702.The apparatus 602′ may be a UE (e.g., a UE 120).

The processing system 702 may be implemented with a bus architecture,represented generally by the bus 704. The bus 704 may include any numberof interconnecting buses and bridges depending on the specificapplication of the processing system 702 and the overall designconstraints. The bus 704 links together various circuits including oneor more processors and/or hardware components, represented by theprocessor 706, the components 604, 606, 608, and the computer-readablemedium/memory 708. The bus 704 may also link various other circuits suchas timing sources, peripherals, voltage regulators, and power managementcircuits, which are well known in the art, and therefore will not bedescribed any further.

The processing system 702 may be coupled to a transceiver 710. Thetransceiver 710 is coupled to one or more antennas 712. The transceiver710 provides a means for communicating with various other apparatusesover a transmission medium. The transceiver 710 receives a signal fromthe one or more antennas 712, extracts information from the receivedsignal, and provides the extracted information to the processing system702, specifically the reception component 604. In addition, thetransceiver 710 receives information from the processing system 702,specifically the transmission component 608, and based at least in parton the received information, generates a signal to be applied to the oneor more antennas 712. The processing system 702 includes a processor 706coupled to a computer-readable medium/memory 708. The processor 706 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 708. The software, whenexecuted by the processor 706, causes the processing system 702 toperform the various functions described herein for any particularapparatus. The computer-readable medium/memory 708 may also be used forstoring data that is manipulated by the processor 706 when executingsoftware. The processing system further includes at least one of thecomponents 604, 606, and 608. The components may be software modulesrunning in the processor 706, resident/stored in the computer readablemedium/memory 708, one or more hardware modules coupled to the processor706, or some combination thereof. The processing system 702 may be acomponent of the UE 120 and may include the memory 282 and/or at leastone of the TX MIMO processor 266, the RX processor 258, and/or thecontroller/processor 280.

In some aspects, the apparatus 602/602′ for wireless communicationincludes means for determining a set of modulations for a random accessmessage associated with a two-step RACH procedure, wherein the set ofmodulations is either a first set of modulations or a second set ofmodulations, the first set of modulations being different from thesecond set of modulations, and wherein the set of modulations isdetermined based at least in part on whether a signal strength satisfiesa signal strength threshold; means for transmitting the random accessmessage based at least in part on the determined set of modulations, therandom access message including a PUSCH modulated using the determinedset of modulations; and/or the like. The aforementioned means may be oneor more of the aforementioned components of the apparatus 602 and/or theprocessing system 702 of the apparatus 602′ configured to perform thefunctions recited by the aforementioned means. As described elsewhereherein, the processing system 702 may include the TX MIMO processor 266,the RX processor 258, and/or the controller/processor 280. In oneconfiguration, the aforementioned means may be the TX MIMO processor266, the RX processor 258, and/or the controller/processor 280configured to perform the functions and/or operations recited herein.

FIG. 7 is provided as an example. Other examples may differ from what isdescribed in connection with FIG. 7.

FIG. 8 is a conceptual data flow diagram 800 illustrating a data flowbetween different components in an example apparatus 802. The apparatus802 may be a base station (e.g., base station 110). In some aspects, theapparatus 802 includes a reception component 804, a determinationcomponent 806, a processing component 808, and/or a transmissioncomponent 810.

In some aspects, one or more components of apparatus 802 may operate toperform one or more operations described herein. For example, receptioncomponent 804 may operate to receive (e.g., from a UE 850) a randomaccess message, associated with a two-step RACH procedure. Determinationcomponent 806 may determine, based at least in part on the random accessmessage, a set of modulations associated with the random access message.Processing component 808 may process the random access message based atleast in part on the determined set of modulations associated with therandom access message. Transmission component 810 may transmit an SSBfor reception by the UE and/or may transmit (e.g., to the UE 850) arandom access response (e.g., msgB) associated with the random accessmessage.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned process 500 of FIG. 5and/or the like. Each block in the aforementioned process 500 of FIG. 5and/or the like may be performed by a component and the apparatus mayinclude one or more of those components. The components may be one ormore hardware components specifically configured to carry out the statedprocesses/algorithm, implemented by a processor configured to performthe stated processes/algorithm, stored within a computer-readable mediumfor implementation by a processor, or some combination thereof.

The number and arrangement of components shown in FIG. 8 are provided asan example. In practice, there may be additional components, fewercomponents, different components, or differently arranged componentsthan those shown in FIG. 8. Furthermore, two or more components shown inFIG. 8 may be implemented within a single component, or a singlecomponent shown in FIG. 8 may be implemented as multiple, distributedcomponents. Additionally, or alternatively, a set of components (e.g.,one or more components) shown in FIG. 8 may perform one or morefunctions described as being performed by another set of componentsshown in FIG. 8.

FIG. 9 is a diagram 900 illustrating an example of a hardwareimplementation for an apparatus 802′ employing a processing system 902.The apparatus 802′ may be a base station (e.g., base station 110).

The processing system 902 may be implemented with a bus architecture,represented generally by the bus 904. The bus 904 may include any numberof interconnecting buses and bridges depending on the specificapplication of the processing system 902 and the overall designconstraints. The bus 904 links together various circuits including oneor more processors and/or hardware components, represented by theprocessor 906, the components 804, 806, 808, 810 and thecomputer-readable medium/memory 908. The bus 904 may also link variousother circuits such as timing sources, peripherals, voltage regulators,and power management circuits, which are well known in the art, andtherefore will not be described any further.

The processing system 902 may be coupled to a transceiver 910. Thetransceiver 910 is coupled to one or more antennas 912. The transceiver910 provides a means for communicating with various other apparatusesover a transmission medium. The transceiver 910 receives a signal fromthe one or more antennas 912, extracts information from the receivedsignal, and provides the extracted information to the processing system902, specifically the reception component 804. In addition, thetransceiver 910 receives information from the processing system 902,specifically the transmission component 810, and based at least in parton the received information, generates a signal to be applied to the oneor more antennas 912. The processing system 902 includes a processor 906coupled to a computer-readable medium/memory 908. The processor 906 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 908. The software, whenexecuted by the processor 906, causes the processing system 902 toperform the various functions described herein for any particularapparatus. The computer-readable medium/memory 908 may also be used forstoring data that is manipulated by the processor 906 when executingsoftware. The processing system further includes at least one of thecomponents 804, 806, 808, and 810. The components may be softwaremodules running in the processor 906, resident/stored in the computerreadable medium/memory 908, one or more hardware modules coupled to theprocessor 906, or some combination thereof. The processing system 902may be a component of the base station 110 and may include the memory242 and/or at least one of the TX MIMO processor 230, the RX processor238, and/or the controller/processor 240.

In some aspects, the apparatus 802/802′ for wireless communicationincludes means for receiving, from a UE (e.g., a UE 120), a randomaccess message associated with a two-step RACH procedure; means fordetermining, based at least in part on the random access message, a setof modulations associated with the random access message, wherein theset of modulations is either a first set of modulations or a second setof modulations, the first set of modulations being different from thesecond set of modulations; means for processing the random accessmessage based at least in part on the determined set of modulationsassociated with the random access message, the random access messageincluding a PUSCH modulated using the determined set of modulations;and/or the like. The aforementioned means may be one or more of theaforementioned components of the apparatus 802 and/or the processingsystem 902 of the apparatus 802′ configured to perform the functionsrecited by the aforementioned means. As described elsewhere herein, theprocessing system 902 may include the TX MIMO processor 230, the receiveprocessor 238, and/or the controller/processor 240. In oneconfiguration, the aforementioned means may be the TX MIMO processor230, the receive processor 238, and/or the controller/processor 240configured to perform the functions and/or operations recited herein.

FIG. 9 is provided as an example. Other examples may differ from what isdescribed in connection with FIG. 9.

The following provides an overview of aspects of the present disclosure:

Aspect 1: A method of wireless communication performed by a userequipment (UE), comprising: determining a set of modulations for arandom access message associated with a two-step random access channel(RACH) procedure, wherein the set of modulations is either a first setof modulations or a second set of modulations, the first set ofmodulations being different from the second set of modulations, andwherein the set of modulations is determined based at least in part onwhether a signal strength satisfies a signal strength threshold; andtransmitting the random access message based at least in part on thedetermined set of modulations, the random access message including aphysical uplink shared channel (PUSCH) modulated using the determinedset of modulations.

Aspect 2: The method of aspect 1, further comprising receiving systeminformation from a base station, wherein the signal strength thresholdis identified in the system information received by the UE.

Aspect 3: The method of any of aspects 1-2, further comprising receivingthe signal strength threshold in system information comprising remainingminimum system information.

Aspect 4: The method of any of aspects 1-3, wherein determining the setof modulations comprises determining the set of modulations to be thefirst set of modulations when the signal strength satisfies the signalstrength threshold and determining the set of modulations to be thesecond set of modulations when the signal strength does not satisfy thesignal strength threshold.

Aspect 5: The method of aspect 4, wherein the second set of modulationsis a π/2 binary phase shift keying scheme.

Aspect 6: The method of any of aspects 1-5, wherein transmitting therandom access message comprises transmitting the random access messagewith an amount of time between a preamble of the random access messageand the PUSCH, wherein the amount of time is based at least in part onthe determined set of modulations.

Aspect 7: The method of aspect 6, wherein the preamble of the randomaccess message is used for channel estimation enhancement of the PUSCH.

Aspect 8: The method of any of aspects 1-7, wherein transmitting therandom access message comprises transmitting the random access messageusing a set of PUSCH resource unit groups, wherein the set of PUSCHresource unit groups when the first set of modulations is determined isdifferent from the set of PUSCH resource unit groups when the second setof modulations is determined.

Aspect 9: The method of any of aspects 1-8, wherein transmitting therandom access message comprises transmitting the random access messagebased on a set of RACH occasions, wherein the set of RACH occasions whenthe first set of modulations is determined is different from the set ofRACH occasions when the second set of modulations is determined.

Aspect 10: The method of any of aspects 1-9, wherein transmitting therandom access message comprises transmitting the random access messagebased on a mapping between a resource allocation for a PUSCH occasionand a RACH occasion, wherein the mapping when the first set ofmodulations is determined is different from the mapping when the secondset of modulations is determined.

Aspect 11: The method of any of aspects 1-10, wherein transmitting therandom access message comprises transmitting a payload of the randomaccess message, wherein the payload when the first set of modulations isdetermined is different from the payload when the second set ofmodulations is determined.

Aspect 12: The method of any of aspects 1-11, transmitting the randomaccess message comprises transmitting a preamble for the random accessmessage, wherein a length of the preamble when the first set ofmodulations is determined is different from the length of the preamblewhen the second set of modulations is determined.

Aspect 13: The method of any of aspects 1-12, wherein transmitting therandom access message comprises applying preamble repetition for therandom access message if the first set of modulations is determined andnot applying preamble repetition if the second set of modulations isdetermined.

Aspect 14: The method of any of aspects 1-13, wherein transmitting therandom access message comprises transmitting a preamble sequence,wherein the preamble sequence when the first set of modulations isdetermined is different from the preamble sequence when the second setof modulations is determined.

Aspect 15: The method of any of aspects 1-14, transmitting the randomaccess message comprises transmitting an indication of the determinedset of modulations, wherein the indication is transmitted via at leastone of a format of a preamble of the random access message, a length ofthe preamble, repetition of the preamble, a preamble sequence, or a setof resources in which the random access message is transmitted.

Aspect 16: The method of any of aspects 1-15, further comprising:receiving a synchronization signal block (SSB); and determining thesignal strength based at least in part on a reference signal receivedpower associated with the SSB.

Aspect 17: A method of wireless communication performed by a basestation, comprising: receiving, from a user equipment (UE), a randomaccess message associated with a two-step random access channel (RACH)procedure; determining, based at least in part on the random accessmessage, a set of modulations associated with the random access message,wherein the set of modulations is either a first set of modulations or asecond set of modulations, the first set of modulations being differentfrom the second set of modulations; and processing the random accessmessage based at least in part on the determined set of modulationsassociated with the random access message, the random access messageincluding a physical uplink shared channel (PUSCH) modulated using thedetermined set of modulations.

Aspect 18: The method of aspect 17, further comprising transmittingsystem information that identifies a signal strength thresholdassociated with determining to use the second set of modulations.

Aspect 19: The method of any of aspects 17-18, further comprisingtransmitting the signal strength threshold in system informationcomprising remaining minimum system information.

Aspect 20: The method of any of aspects 17-19, wherein the second set ofmodulations is a π/2 binary phase shift keying scheme.

Aspect 21: The method of any of aspects 17-20, wherein receiving therandom access message comprises receiving the random access message withan amount of time between a preamble of the random access message andthe PUSCH, wherein the amount of time is based at least in part on thedetermined set of modulations.

Aspect 22: The method of aspect 21, wherein the preamble of the randomaccess message is used for channel estimation enhancement of the PUSCH.

Aspect 23: The method of any of aspects 17-22, receiving the randomaccess message comprises receiving the random access message using a setof PUSCH resource unit groups, wherein the set of PUSCH resource unitgroups when the first set of modulations is determined is different fromthe set of PUSCH resource unit groups when the second set of modulationsis determined.

Aspect 24: The method of any of aspects 17-23, wherein receiving therandom access message comprises receiving the random access messagebased on a set of RACH occasions, wherein the set of RACH occasions whenthe first set of modulations is determined is different from the set ofRACH occasions when the second set of modulations is determined.

Aspect 25: The method of any of aspects 17-24, wherein receiving therandom access message comprises receiving the random access messagebased on a mapping between a resource allocation for a PUSCH occasionand a RACH occasion, wherein the mapping when the first set ofmodulations is determined is different from the mapping when the secondset of modulations is determined.

Aspect 26: The method of any of aspects 17-25, wherein receiving therandom access message comprises receiving a payload of the random accessmessage, wherein the payload when the first set of modulations isdetermined is different from the payload when the second set ofmodulations is determined.

Aspect 27: The method of any of aspects 17-26, further comprisingtransmitting a synchronization signal block (SSB) to enable adetermination of a signal strength of a reference signal received powerassociated with the SSB.

Aspect 28: The method of any of aspects 17-27, wherein receiving therandom access message comprises receiving a preamble for the randomaccess message, wherein a length of the preamble when the first set ofmodulations is determined is different from the length of the preamblewhen the second set of modulations is determined.

Aspect 29: The method of any of aspects 17-28, wherein receiving therandom access message comprises applying preamble repetition for therandom access message if the first set of modulations is determined andnot applying preamble repetition if the second set of modulations isdetermined.

Aspect 30: The method of any of aspects 17-29, wherein receiving therandom access message comprises receiving a preamble sequence, whereinthe preamble sequence when the first set of modulations is determined isdifferent from the preamble sequence when the second set of modulationsis determined.

Aspect 31: The method of any of aspects 17-30, determining the set ofmodulations comprises receiving an indication of the determined set ofmodulations, wherein the indication is received via at least one of aformat of a preamble of the random access message, a length of thepreamble, repetition of the preamble, a preamble sequence, or a set ofresources in which the random access message is received.

Aspect 32: An apparatus for wireless communication at a device,comprising a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to perform the method of one or more aspects ofaspects 1-16.

Aspect 33: A device for wireless communication, comprising a memory andone or more processors coupled to the memory, the memory and the one ormore processors configured to perform the method of one or more aspectsof aspects 1-16.

Aspect 34: An apparatus for wireless communication, comprising at leastone means for performing the method of one or more aspects of aspects1-16.

Aspect 35: A non-transitory computer-readable medium storing code forwireless communication, the code comprising instructions executable by aprocessor to perform the method of one or more aspects of aspects 1-16.

Aspect 36: A non-transitory computer-readable medium storing a set ofinstructions for wireless communication, the set of instructionscomprising one or more instructions that, when executed by one or moreprocessors of a device, cause the device to perform the method of one ormore aspects of aspects 1-16.

Aspect 37: An apparatus for wireless communication at a device,comprising a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to perform the method of one or more aspects ofaspects 17-31.

Aspect 38: A device for wireless communication, comprising a memory andone or more processors coupled to the memory, the memory and the one ormore processors configured to perform the method of one or more aspectsof aspects 17-31.

Aspect 39: An apparatus for wireless communication, comprising at leastone means for performing the method of one or more aspects of aspects17-31.

Aspect 40: A non-transitory computer-readable medium storing code forwireless communication, the code comprising instructions executable by aprocessor to perform the method of one or more aspects of aspects 17-31.

Aspect 41: A non-transitory computer-readable medium storing a set ofinstructions for wireless communication, the set of instructionscomprising one or more instructions that, when executed by one or moreprocessors of a device, cause the device to perform the method of one ormore aspects of aspects 17-31.

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the aspects to the preciseform disclosed. Modifications and variations may be made in light of theabove disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construedas hardware, firmware, and/or a combination of hardware and software. Asused herein, a processor is implemented in hardware, firmware, and/or acombination of hardware and software.

As used herein, satisfying a threshold may, depending on the context,refer to a value being greater than the threshold, greater than or equalto the threshold, less than the threshold, less than or equal to thethreshold, equal to the threshold, not equal to the threshold, and/orthe like.

It will be apparent that systems and/or methods described herein may beimplemented in different forms of hardware, firmware, and/or acombination of hardware and software. The actual specialized controlhardware or software code used to implement these systems and/or methodsis not limiting of the aspects. Thus, the operation and behavior of thesystems and/or methods were described herein without reference tospecific software code—it being understood that software and hardwarecan be designed to implement the systems and/or methods based, at leastin part, on the description herein.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of various aspects. In fact, many ofthese features may be combined in ways not specifically recited in theclaims and/or disclosed in the specification. Although each dependentclaim listed below may directly depend on only one claim, the disclosureof various aspects includes each dependent claim in combination withevery other claim in the claim set. A phrase referring to “at least oneof” a list of items refers to any combination of those items, includingsingle members. As an example, “at least one of: a, b, or c” is intendedto cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combinationwith multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c,a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering ofa, b, and c).

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems, and may be used interchangeably with “one or more.” Furthermore,as used herein, the terms “set” and “group” are intended to include oneor more items (e.g., related items, unrelated items, a combination ofrelated and unrelated items, and/or the like), and may be usedinterchangeably with “one or more.” Where only one item is intended, thephrase “only one” or similar language is used. Also, as used herein, theterms “has,” “have,” “having,” and/or the like are intended to beopen-ended terms. Further, the phrase “based on” is intended to mean“based, at least in part, on” unless explicitly stated otherwise.

What is claimed is:
 1. A method of wireless communication performed by auser equipment (UE), comprising: determining a set of modulations for arandom access message associated with a two-step random access channel(RACH) procedure, wherein the set of modulations is either a first setof modulations or a second set of modulations, the first set ofmodulations being different from the second set of modulations, andwherein the set of modulations is determined based at least in part onwhether a signal strength satisfies a signal strength threshold; andtransmitting the random access message based at least in part on thedetermined set of modulations, the random access message including aphysical uplink shared channel (PUSCH) modulated using the determinedset of modulations.
 2. The method of claim 1, further comprisingreceiving system information from a base station, wherein the signalstrength threshold is identified in the system information received bythe UE.
 3. The method of claim 1, further comprising receiving thesignal strength threshold in system information comprising remainingminimum system information.
 4. The method of claim 1, whereindetermining the set of modulations comprises determining the set ofmodulations to be the first set of modulations when the signal strengthsatisfies the signal strength threshold and determining the set ofmodulations to be the second set of modulations when the signal strengthdoes not satisfy the signal strength threshold.
 5. The method of claim4, wherein the second set of modulations is a π/2 binary phase shiftkeying scheme.
 6. The method of claim 1, wherein transmitting the randomaccess message comprises transmitting the random access message with anamount of time between a preamble of the random access message and thePUSCH, wherein the amount of time is based at least in part on thedetermined set of modulations.
 7. The method of claim 6, wherein thepreamble of the random access message is used for channel estimationenhancement of the PUSCH.
 8. The method of claim 1, wherein transmittingthe random access message comprises transmitting the random accessmessage using a set of PUSCH resource unit groups, wherein the set ofPUSCH resource unit groups when the first set of modulations isdetermined is different from the set of PUSCH resource unit groups whenthe second set of modulations is determined.
 9. The method of claim 1,wherein transmitting the random access message comprises transmittingthe random access message based on a set of RACH occasions, wherein theset of RACH occasions when the first set of modulations is determined isdifferent from the set of RACH occasions when the second set ofmodulations is determined.
 10. The method of claim 1, whereintransmitting the random access message comprises transmitting the randomaccess message based on a mapping between a resource allocation for aPUSCH occasion and a RACH occasion, wherein the mapping when the firstset of modulations is determined is different from the mapping when thesecond set of modulations is determined.
 11. The method of claim 1,wherein transmitting the random access message comprises transmitting apayload of the random access message, wherein the payload when the firstset of modulations is determined is different from the payload when thesecond set of modulations is determined.
 12. The method of claim 1,wherein transmitting the random access message comprises transmitting apreamble for the random access message, wherein a length of the preamblewhen the first set of modulations is determined is different from thelength of the preamble when the second set of modulations is determined.13. The method of claim 1, wherein transmitting the random accessmessage comprises applying preamble repetition for the random accessmessage if the first set of modulations is determined and not applyingpreamble repetition if the second set of modulations is determined. 14.The method of claim 1, wherein transmitting the random access messagecomprises transmitting a preamble sequence, wherein the preamblesequence when the first set of modulations is determined is differentfrom the preamble sequence when the second set of modulations isdetermined.
 15. The method of claim 1, wherein transmitting the randomaccess message comprises transmitting an indication of the determinedset of modulations, wherein the indication is transmitted via at leastone of a format of a preamble of the random access message, a length ofthe preamble, repetition of the preamble, a preamble sequence, or a setof resources in which the random access message is transmitted.
 16. Themethod of claim 1, further comprising: receiving a synchronizationsignal block (SSB); and determining the signal strength based at leastin part on a reference signal received power associated with the SSB.17. A method of wireless communication performed by a base station,comprising: receiving, from a user equipment (UE), a random accessmessage associated with a two-step random access channel (RACH)procedure; determining, based at least in part on the random accessmessage, a set of modulations associated with the random access message,wherein the set of modulations is either a first set of modulations or asecond set of modulations, the first set of modulations being differentfrom the second set of modulations; and processing the random accessmessage based at least in part on the determined set of modulationsassociated with the random access message, the random access messageincluding a physical uplink shared channel (PUSCH) modulated using thedetermined set of modulations.
 18. The method of claim 17, furthercomprising transmitting system information that identifies a signalstrength threshold associated with determining to use the second set ofmodulations.
 19. The method of claim 17, wherein the second set ofmodulations is a π/2 binary phase shift keying scheme.
 20. The method ofclaim 17, wherein receiving the random access message comprisesreceiving the random access message with an amount of time between apreamble of the random access message and the PUSCH, wherein the amountof time is based at least in part on the determined set of modulations.21. The method of claim 17, wherein receiving the random access messagecomprises receiving the random access message using a set of PUSCHresource unit groups, wherein the set of PUSCH resource unit groups whenthe first set of modulations is determined is different from the set ofPUSCH resource unit groups when the second set of modulations isdetermined.
 22. The method of claim 17, wherein receiving the randomaccess message comprises receiving the random access message based on aset of RACH occasions, wherein the set of RACH occasions when the firstset of modulations is determined is different from the set of RACHoccasions when the second set of modulations is determined.
 23. Themethod of claim 17, wherein receiving the random access messagecomprises receiving the random access message based on a mapping betweena resource allocation for a PUSCH occasion and a RACH occasion, whereinthe mapping when the first set of modulations is determined is differentfrom the mapping when the second set of modulations is determined. 24.The method of claim 17, wherein receiving the random access messagecomprises receiving a payload of the random access message, wherein thepayload when the first set of modulations is determined is differentfrom the payload when the second set of modulations is determined. 25.The method of claim 17, wherein receiving the random access messagecomprises receiving a preamble for the random access message, wherein alength of the preamble when the first set of modulations is determinedis different from the length of the preamble when the second set ofmodulations is determined.
 26. The method of claim 17, wherein receivingthe random access message comprises applying preamble repetition for therandom access message if the first set of modulations is determined andnot applying preamble repetition if the second set of modulations isdetermined.
 27. The method of claim 17, wherein receiving the randomaccess message comprises receiving a preamble sequence, wherein thepreamble sequence when the first set of modulations is determined isdifferent from the preamble sequence when the second set of modulationsis determined.
 28. The method of claim 17, wherein determining the setof modulations comprises receiving an indication of the determined setof modulations, wherein the indication is received via at least one of aformat of a preamble of the random access message, a length of thepreamble, repetition of the preamble, a preamble sequence, or a set ofresources in which the random access message is received.
 29. A userequipment (UE) for wireless communication, comprising: a memory; and oneor more processors operatively coupled to the memory, the memory and theone or more processors configured to: determine a set of modulations fora random access message associated with a two-step random access channel(RACH) procedure, wherein the set of modulations is either a first setof modulations or a second set of modulations, the first set ofmodulations being different from the second set of modulations, andwherein the set of modulations is determined based at least in part onwhether a signal strength satisfies a signal strength threshold; andtransmit the random access message based at least in part on thedetermined set of modulations, the random access message including aphysical uplink shared channel (PUSCH) modulated using the determinedset of modulations.
 30. A base station for wireless communication,comprising: a memory; and one or more processors operatively coupled tothe memory, the memory and the one or more processors configured to:receive, from a user equipment (UE), a random access message associatedwith a two-step random access channel (RACH) procedure; determine, basedat least in part on the random access message, a set of modulationsassociated with the random access message, wherein the set ofmodulations is either a first set of modulations or a second set ofmodulations, the first set of modulations being different from thesecond set of modulations; and process the random access message basedat least in part on the determined set of modulations associated withthe random access message, the random access message including aphysical uplink shared channel (PUSCH) modulated using the determinedset of modulations.